Tufts composed of a plurality of filaments for oral care implements, like manual and powered toothbrushes, are well known in the art. Generally, the tufts are attached to a bristle carrier or mounting surface of a head intended for insertion into a user's oral cavity. A grip handle is usually attached to the head, which handle is held by the user during brushing. The head is either permanently connected or repeatedly attachable to and detachable from the handle.
In order to clean teeth effectively, appropriate contact pressure has to be provided between the free ends of the filaments and the teeth. Generally, the contact pressure depends on the bending stiffness and the displacement of the filaments, while the bending stiffness of a single filament depends on its length and cross sectional area. Usually, filaments with greater length show lower bending stiffness as compared to shorter filaments. However, relatively thin filaments tend to flex away easily and the relatively low bending stiffness results in reduced plaque removal efficiency on teeth surfaces, as well as in less interdental penetrations properties and cleaning performance. In order to compensate said reduction in bending stiffness of longer filaments, the size of the cross sectional area of a filament could be increased. However, relatively thick filaments may create an unpleasant brushing sensation and tend to injure the gums in the oral cavity.
Further, tuft patterns composed of filaments having tapered or flagged free ends are also known in the art. Such filaments should improve cleaning properties of oral care implements during normal use. In particular, the relatively thin ends of the filaments should provide improved interdental penetration in the interproximal areas during a brushing process to improve removal of plaque and other residuals in these hard to reach areas.
While these toothbrushes may clean interdental areas adequately, they are generally not as well suited to provide adequate removal of plaque and debris from the buccal and lingual surface via a scrubbing and polishing action since its bending stiffness is not sufficiently high.
In order to achieve and preserve good oral health, and to prevent gingivitis, it is important to clean both, substantially flat tooth surface via a scrubbing and polishing action, as well as along the gum line and in interdental areas, in particular in the region of the back molars. Further gaps between teeth and periodontium, the so called gingival groove has to be thoroughly cleaned. It is known that a lack of good removal of plaque in the gingival groove can cause gingivitis, i.e. inflammation of the gum tissue. Additionally, standard tufts do not provide sufficient capillary effects to remove plaque and debris from the teeth and gums during brushing. However, in order to achieve good cleaning results, the plaque must be reached by the tufts/filaments, then the plaque must be disrupted and, finally, taken away. Further, the tufts shall provide good sensory feeling on the gums during brushing.
Additionally, the mechanical stress occurring within flagged or tapered filaments during a brushing process leads to higher stress in the tips of the filaments as compared to circular-shaped filaments. This means, in tufts having the same overall stiffness, flagged or tapered filaments have to bear higher maximum stress values as compared to circular-shaped filaments. This increased stress in the individual filaments can lead to an increased wear behavior during usage. This wear is characterized by an increased splay of the tuft which leads to less consumer acceptance.
It is an object of the present disclosure to provide a head for an oral care implement which overcomes at least one of the above-mentioned drawbacks. It is also an object of the present disclosure to provide an oral care implement comprising such head, and a method for manufacturing said head.